Kernel: T8147: drop out-of-tree INOTIFY_STACKFS patch

The inotify support for overlayfs is no longer needed. Native upstream support
landed in kernel 4.16 (commit 31747eda41ef/764baba80168 in 2018, which made
overlayfs hash inodes by their lower inode so fsnotify works on overlay mounts),
and kernel 6.8 (commit bc2473c90fca in 2023) extended it so fsnotify generates
events for operations on the real underlying files of an overlay.

The patch was an out-of-tree workaround that never went upstream and predates
these solutions.

2 files changed, 0 insertions, 300 deletions

diff --git a/scripts/package-build/linux-kernel/config/00-filesystems.config b/scripts/package-build/linux-kernel/config/00-filesystems.config
index a17fd36c..3b9191e9 100644
--- a/scripts/package-build/linux-kernel/config/00-filesystems.config
+++ b/scripts/package-build/linux-kernel/config/00-filesystems.config
@@ -38,7 +38,6 @@ CONFIG_FILE_LOCKING=y
 CONFIG_FSNOTIFY=y
 CONFIG_DNOTIFY=y
 CONFIG_INOTIFY_USER=y
-CONFIG_INOTIFY_STACKFS=y
 # CONFIG_FANOTIFY is not set
 # CONFIG_QUOTA is not set
 CONFIG_AUTOFS_FS=m
diff --git a/scripts/package-build/linux-kernel/patches/kernel/0002-inotify-support-for-stackable-filesystems.patch b/scripts/package-build/linux-kernel/patches/kernel/0002-inotify-support-for-stackable-filesystems.patch
deleted file mode 100644
index 115f6831..00000000
--- a/scripts/package-build/linux-kernel/patches/kernel/0002-inotify-support-for-stackable-filesystems.patch
+++ /dev/null
@@ -1,299 +0,0 @@
-From 1d625d2f745b61a718ce52cd1729f467c17defa6 Mon Sep 17 00:00:00 2001
-From: Alex Harpin <development@landsofshadow.co.uk>
-Date: Wed, 31 Dec 2014 10:33:38 +0000
-Subject: [PATCH] VyOS: add inotify support for stackable filesystems
- (overlayfs)
-
-As it stands at the moment, overlayfs doesn't have full support for
-inotify, and as such anything that relies on inotify currently has
-issues.  The simplest method of demonstrating this is to tail a file
-(so tail -f /var/log/messages) and see that it doesn't follow changes
-in that file.  This has been reported in a number of places, including
-Bug #882147 in Ubuntu.  This patch is based on the version proposed by
-Li Jianguo in response to this bug, adding support for inotify in
-stackable filesystems.
-
-This commit provides a complete fix for the workaround implemented
-for bug #303, and will allow that commit to be reverted.
-
-Bug #425 http://bugzilla.vyos.net/show_bug.cgi?id=425
-
-(cherry picked from commit a93f1128bc83b5a6628da242e71c18ef05e81ea2)
-
----
- fs/notify/inotify/Kconfig        |   9 +++
- fs/notify/inotify/inotify_user.c | 114 ++++++++++++++++++++++++++++++-
- fs/overlayfs/super.c             |  27 ++++++--
- include/linux/inotify.h          |  28 ++++++++
- 4 files changed, 172 insertions(+), 6 deletions(-)
-
-diff --git a/fs/notify/inotify/Kconfig b/fs/notify/inotify/Kconfig
-index 1cc8be25df7e..bc4acd1a6ea4 100644
---- a/fs/notify/inotify/Kconfig
-+++ b/fs/notify/inotify/Kconfig
-@@ -15,3 +15,12 @@ config INOTIFY_USER
- 	  For more information, see <file:Documentation/filesystems/inotify.rst>
- 
- 	  If unsure, say Y.
-+
-+config INOTIFY_STACKFS
-+	bool "Inotify support for stackable filesystem"
-+	select INOTIFY_USER
-+	default y
-+	help
-+	  Say Y here to enable inotify support for stackable filesystem.
-+
-+	  If unsure, say N.
-diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
-index 1c4bfdab008d..cf567cc33679 100644
---- a/fs/notify/inotify/inotify_user.c
-+++ b/fs/notify/inotify/inotify_user.c
-@@ -15,6 +15,7 @@
- 
- #include <linux/file.h>
- #include <linux/fs.h> /* struct inode */
-+#include <linux/mount.h>
- #include <linux/fsnotify_backend.h>
- #include <linux/idr.h>
- #include <linux/init.h> /* fs_initcall */
-@@ -97,6 +98,93 @@ static void __init inotify_sysctls_init(void)
- #define inotify_sysctls_init() do { } while (0)
- #endif /* CONFIG_SYSCTL */
- 
-+#ifdef CONFIG_INOTIFY_STACKFS
-+
-+static DEFINE_RWLOCK(inotify_fs_lock);
-+static LIST_HEAD(inotify_fs_list);
-+
-+static inline struct file_system_type* peek_fs_type(struct path *path)
-+{
-+	return path->mnt->mnt_sb->s_type;
-+}
-+
-+static struct inotify_stackfs* inotify_get_stackfs(struct path *path)
-+{
-+	struct file_system_type *fs;
-+	struct inotify_stackfs *fse, *ret = NULL;
-+
-+	fs = peek_fs_type(path);
-+
-+	read_lock(&inotify_fs_lock);
-+	list_for_each_entry(fse, &inotify_fs_list, list) {
-+	if (fse->fs_type == fs) {
-+		ret = fse;
-+		break;
-+	}
-+	}
-+	read_unlock(&inotify_fs_lock);
-+
-+	return ret;
-+}
-+
-+static inline void inotify_put_stackfs(struct inotify_stackfs *fs)
-+{
-+}
-+
-+int inotify_register_stackfs(struct inotify_stackfs *fs)
-+{
-+	int ret = 0;
-+	struct inotify_stackfs *fse;
-+
-+	BUG_ON(IS_ERR_OR_NULL(fs->fs_type));
-+	BUG_ON(IS_ERR_OR_NULL(fs->func));
-+
-+	INIT_LIST_HEAD(&fs->list);
-+
-+	write_lock(&inotify_fs_lock);
-+	list_for_each_entry(fse, &inotify_fs_list, list) {
-+		if (fse->fs_type == fs->fs_type) {
-+			write_unlock(&inotify_fs_lock);
-+			ret = -EBUSY;
-+			goto out;
-+		}
-+	}
-+	list_add_tail(&fs->list, &inotify_fs_list);
-+	write_unlock(&inotify_fs_lock);
-+
-+out:
-+	return ret;
-+}
-+EXPORT_SYMBOL_GPL(inotify_register_stackfs);
-+
-+void inotify_unregister_stackfs(struct inotify_stackfs *fs)
-+{
-+	struct inotify_stackfs *fse, *n;
-+
-+	write_lock(&inotify_fs_lock);
-+	list_for_each_entry_safe(fse, n, &inotify_fs_list, list) {
-+		if (fse == fs) {
-+			list_del(&fse->list);
-+			break;
-+		}
-+	}
-+	write_unlock(&inotify_fs_lock);
-+}
-+EXPORT_SYMBOL_GPL(inotify_unregister_stackfs);
-+
-+#else
-+
-+static inline struct inotify_stackfs* inotify_get_stackfs(struct path *path)
-+{
-+	return NULL;
-+}
-+
-+static inline void inotify_put_stackfs(struct inotify_stackfs *fs)
-+{
-+}
-+
-+#endif /* CONFIG_INOTIFY_STACKFS */
-+
- static inline __u32 inotify_arg_to_mask(struct inode *inode, u32 arg)
- {
- 	__u32 mask;
-@@ -370,8 +458,8 @@ static const struct file_operations inotify_fops = {
- /*
-  * find_inode - resolve a user-given path to a specific inode
-  */
--static int inotify_find_inode(const char __user *dirname, struct path *path,
--						unsigned int flags, __u64 mask)
-+static inline int __inotify_find_inode(const char __user *dirname, struct path *path,
-+					unsigned int flags, __u64 mask)
- {
- 	int error;
- 
-@@ -392,6 +480,28 @@ static int inotify_find_inode(const char __user *dirname, struct path *path,
- 	return error;
- }
- 
-+static int inotify_find_inode(const char __user *dirname, struct path *path,
-+					unsigned int flags, __u64 mask)
-+{
-+	int ret;
-+	struct path tpath;
-+	struct inotify_stackfs *fse;
-+
-+	ret = __inotify_find_inode(dirname, &tpath, flags, mask);
-+	if (ret)
-+		return ret;
-+	fse = inotify_get_stackfs(&tpath);
-+	if (fse == NULL) {
-+		*path = tpath;
-+		return 0;
-+	}
-+	ret = fse->func(path, &tpath);
-+	inotify_put_stackfs(fse);
-+	path_put(&tpath);
-+
-+	return ret;
-+}
-+
- static int inotify_add_to_idr(struct idr *idr, spinlock_t *idr_lock,
- 			      struct inotify_inode_mark *i_mark)
- {
-diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
-index 93ee57bc82ad..5f4f886d011e 100644
---- a/fs/overlayfs/super.c
-+++ b/fs/overlayfs/super.c
-@@ -15,6 +15,7 @@
- #include <linux/seq_file.h>
- #include <linux/posix_acl_xattr.h>
- #include <linux/exportfs.h>
-+#include <linux/inotify.h>
- #include <linux/file.h>
- #include <linux/fs_context.h>
- #include <linux/fs_parser.h>
-@@ -1533,6 +1534,18 @@ static void ovl_inode_init_once(void *foo)
- 	inode_init_once(&oi->vfs_inode);
- }
- 
-+static int ovl_inotify_path(struct path *dst, struct path *src)
-+{
-+	ovl_path_real(src->dentry, dst);
-+	path_get(dst);
-+	return 0;
-+}
-+
-+static struct inotify_stackfs ovl_inotify = {
-+	.fs_type	= &ovl_fs_type,
-+	.func		= ovl_inotify_path,
-+};
-+
- static int __init ovl_init(void)
- {
- 	int err;
-@@ -1548,18 +1561,24 @@ static int __init ovl_init(void)
- 	err = ovl_aio_request_cache_init();
- 	if (!err) {
- 		err = register_filesystem(&ovl_fs_type);
--		if (!err)
--			return 0;
-+		if (err)
-+			goto err;
-+		err = inotify_register_stackfs(&ovl_inotify);
-+		if (err)
-+			goto err;
-+		return 0;
- 
--		ovl_aio_request_cache_destroy();
- 	}
-+err:
- 	kmem_cache_destroy(ovl_inode_cachep);
--
-+	unregister_filesystem(&ovl_fs_type);
-+	ovl_aio_request_cache_destroy();
- 	return err;
- }
- 
- static void __exit ovl_exit(void)
- {
-+	inotify_unregister_stackfs(&ovl_inotify);
- 	unregister_filesystem(&ovl_fs_type);
- 
- 	/*
-diff --git a/include/linux/inotify.h b/include/linux/inotify.h
-index 8d20caa1b268..c126e2f93a73 100644
---- a/include/linux/inotify.h
-+++ b/include/linux/inotify.h
-@@ -8,6 +8,8 @@
- #define _LINUX_INOTIFY_H
- 
- #include <uapi/linux/inotify.h>
-+#include <linux/list.h>
-+#include <linux/fs.h>
- 
- #define ALL_INOTIFY_BITS (IN_ACCESS | IN_MODIFY | IN_ATTRIB | IN_CLOSE_WRITE | \
- 			  IN_CLOSE_NOWRITE | IN_OPEN | IN_MOVED_FROM | \
-@@ -17,4 +19,30 @@
- 			  IN_DONT_FOLLOW | IN_EXCL_UNLINK | IN_MASK_ADD | \
- 			  IN_MASK_CREATE | IN_ISDIR | IN_ONESHOT)
- 
-+typedef int (*inotify_path_proc)(struct path *dst, struct path *src);
-+
-+struct inotify_stackfs {
-+	struct list_head	list;		/* entry in inotify_fs_list */
-+	struct file_system_type	*fs_type;	/* registed file_system_type */
-+	inotify_path_proc	func;		/* registed callback function */
-+};
-+
-+#ifdef CONFIG_INOTIFY_STACKFS
-+
-+extern int inotify_register_stackfs(struct inotify_stackfs *fs);
-+extern void inotify_unregister_stackfs(struct inotify_stackfs *fs);
-+
-+#else
-+
-+static inline int inotify_register_stackfs(struct inotify_stackfs *fs)
-+{
-+	return 0;
-+}
-+
-+static inline void inotify_unregister_stackfs(struct inotify_stackfs *fs)
-+{
-+}
-+
-+#endif	/* CONFIG_INOTIFY_STACKFS */
-+
- #endif	/* _LINUX_INOTIFY_H */
--- 
-2.39.5
-